Effects of mandibular odontogenic keratocyst surgery and removable partial prostheses on masticatory performance

STATEMENT OF PROBLEM: Surgical treatment of odontogenic keratocysts often results in tooth loss. However, information about the effects of different surgical methods and postoperative prosthetic therapy on masticatory performance is lacking. PURPOSE: The purpose of this study was to compare tooth loss following odontogenic keratocyst treatment by enucleation, segmental mandibulectomy with reconstruction, or marsupialization, and the resultant effect on masticatory performance with and without removable partial dentures (RPDs). MATERIAL AND METHODS: Patients with odontogenic keratocysts of the mandible were treated with either enucleation (n=33), segmental mandibulectomy and immediate autogenous bone reconstruction (n=18), or marsupialization in combination with secondary enucleation (n=9). Clinical and radiographic examinations were used to assess the number of teeth with cyst involvement preoperatively and the number of teeth lost following cyst treatment. Masticatory performance with peanuts was measured after cyst treatment both with and without an RPD. The differences in the number of the teeth involved preoperatively and lost postoperatively were compared among the 3 groups with a chi square test for trend. The absorbance value (reflecting masticatory performance) difference among the 3 groups preprosthesis and postprosthesis was analyzed using a 1-way analysis of variance (ANOVA), respectively. The pre- and postprosthetic comparison was made within each group, and a paired t test was used. Age was compared using 1-way ANOVA among 3 groups. Gender was compared using the chi square test (alpha=.05). RESULTS: Although the average number of teeth involved preoperatively with the cyst was similar among the 3 treatment groups, the number of teeth lost following marsupialization was significantly less than the number lost following enucleation or segmental mandibulectomy. Prior to provision of an RPD, mean masticatory performance (mean absorbance value of 0.36+/-0.08) in subjects receiving segmental mandibulectomy was significantly lower than for subjects receiving enucleation (0.52+/-0.15) or marsupialization (0.89+/-0.12) (P<.01). Provision of an RPD significantly increased masticatory performance in subjects who were treated by enucleation or segmental mandibulectomy (P<.01). CONCLUSION: Masticatory performance following odontogenic keratocyst surgery is related to the number of lost teeth, which is a function of the operative method used. Restoration with an RPD postoperatively may improve masticatory function when multiple teeth are lost following enucleation or segmental mandibulectomy.